The present invention relates generally to electric power supply systems, and more specifically to a pulse sharpening circuit for decreasing the current and voltage risetimes of pulse power devices. It is useful in many systems ranging from the particle beam fusion accelerator, field emission electron guns, and intense microwave sources requiring an extremely quick high power turn-on for proper operation.
Modern lasers, electron gun systems, and radar devices use electrical power supplies that include pulse generators that supply high voltage (around 500 kV) for high repetition, fast risetime electrical pulses. Gas laser systems rely on such pulse generators to provide electrical pulses to excite a gas mixture to excited energy states for stimulated emission. Unfortunately, most commonly achieved risetimes range between 5 to 20 nanoseconds.
The task of enhancing the risetimes of pulse generator system is alleviated, to some extent, by the systems disclosed in the following U.S. Patents, the disclosures of which are specifically incorporated herein by reference:
U.S. Pat. No. 4,494,011 issued to Davis; PA0 U.S. Pat. No. 4,546,268 issued to Caldwell et al; and PA0 U.S. Pat. No. 4,549,091 issued to Fahlen et al.
Fahlen et al disclose an excitation circuit for gas lasers which includes a cascaded magnetic charging circuit formed with saturable inductor switches. The saturable inductor switch and magnetic diode charging inductor includes a polyvinyl chloride tube as part of a saturable switch.
The Davis reference has a high voltage pulse generator which provides pulse voltages in the kilovolt range with risetimes to 200 picoseconds. Caldwell et al disclose a transistor circuit capable of generating sub-nanosecond pulses.
Both the Davis ad Caldwell pulse generators are superior in risetime performance to conventional pulse generators. However, both of these prior art systems are complex alternatives to existing pulse generators, rather than improvements made to existing systems. The Davis system uses a high voltage avalanche source, a plurality of biased triode amplifier tubes and circuits and a voltage step-down transformer between any two consecutive tube stages to form a new pulse generator.
From the foregoing discussion, it is apparent that there remains a need to enhance the risetime performance of existing pulse generators, and to enable them to supply pulses with high voltage and high power with subnanosecond current and voltage risetimes. The present invention is intended to satisfy that need.